The present invention relates to a technology for producing a moving picture of a satisfactory picture quality that reflects characteristics of display units and opinions from users.
In the moving picture coding system like the MPEG, it is essential to perform an optimum control of coding parameters. This is essential in order to provide users with a high-quality picture reproduction service with small quantity of moving picture data, or in order to obtain a high-quality picture in a portable moving-picture reproduction terminal that has a limited data storage capacity.
According to a conventional optimization method for optimizing coding parameters, much attention has not been paid to the characteristics of display units which display moving pictures. Instead, coding parameters have been optimized frequently. Those optimized coding parameters include a frame rate (fps: frame per second), a data rate (bps: bit per second), resolution (HXC: line per pixel), a quantization level after a discrete cosine conversion, a macro block type, a macro block pattern (CBP: coded patter block), and a motion vector detection mode.
There exist various types of displays which display moving pictures. Examples of such displays are cathode ray tubes (CRT""s) and TFT type liquid crystal displays (LCD""s), STN type LCD""s, low-temperature polysilicone type LCD""s, and plasma displays. Each display unit provides a unique display different from displays of other types of display units. However, according to the conventional technique, coding parameters of each display unit have not been sufficiently optimized.
According to the conventional technique, the coding control of the moving picture coding apparatuses have not sufficiently reflected users"" feelings and preference about pictures reproduced from these apparatuses. Therefore, the picture quality of moving pictures has not been sufficiently optimized for the users.
According to the conventional technique, in coding moving pictures, frequently, coding parameters such as a frame rate and a bit rate have always been constant regardless of the screen size (inch) of the display unit. Therefore, there have been many problems. For example, the picture quality of the reproduced picture is not good, and the motion of the moving picture cannot be sufficiently recognized because of a low frame rate. Further, as the bit rate is higher than is necessary, the time allowance for recording on a recording medium becomes short.
It is an object of the present invention to provide a moving picture coding control apparatus capable of achieving a satisfactory reproduction of moving pictures reflecting characteristics of display units which display moving picture data and opinions from a plurality of users, through the optimization of coding parameters of a moving picture coding apparatus by reflecting the display unit characteristics and user opinions and evaluations.
It is another object of the present invention to provide a moving picture coding control database generating apparatus capable of generating a database of coding parameters to make it possible to achieve a satisfactory reproduction of moving pictures reflecting characteristics of display units which display moving picture data and opinions from a plurality of users.
Other objects and features of this invention will become apparent from the following description with reference to the accompanying drawings.